JP2011238500A - Connection structure and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection structure having a stable electric property over time, in which galvanic corrosion, i.e. corrosion caused in a conductor in contact with a connection terminal made of a metal more precious than a metal that the conductor is made of, is prevented from occurring, and to provide a manufacturing method of the connection structure.SOLUTION: A connection structure 1 includes: a covered electric cable 40 having a conductor 43 covered with an insulative covering 41 and a cable-tip portion 42 composed of a tip portion of the conductor 43 stripped of the insulative covering 41 and bared; a connection terminal 10 having a cable connection 12 to connect the cable-tip portion 42 with and made of a metal more precious than a metal that the conductor 43 is made of; and an insulating resin 50 sealing the cable-tip portion 42 connected with the cable connection 12. The insulating resin 50 consists of two or more kinds of resins different in the viscosity before hardening.

Description

  The present invention relates to a connection structure as an electric wire with a connection terminal attached to, for example, a connector for connecting an automobile wire harness. More specifically, the present invention is more noble than a conductor of a wire harness and a metal constituting the conductor. The present invention relates to a connection structure with a connection terminal made of metal.

  In the fields of automobiles, office automation equipment, and home appliances, copper wires having a core wire made of a copper-based material having excellent electrical conductivity have been used as signal lines and power lines. In particular, in the automobile field, since high performance and high functionality of vehicles have been rapidly advanced, there is a tendency that the number of electric wires used increases with the increase of various electric devices and control devices mounted on the vehicle. is the current situation.

  On the other hand, demands for improving fuel efficiency by reducing the weight of vehicles are increasing rapidly, and aluminum wires that are lighter and cheaper than copper wires are attracting particular attention in the automotive field.

However, when an aluminum electric wire is actually used for automobiles, there arises a problem that different metal contact corrosion (electric corrosion) occurs.
Specifically, when the metal material constituting each of the connection terminal and the conductor of the electric wire is a different metal material, if an electrolyte such as water adheres to the connection portion between the connection terminal and the conductor, the standard electrode potential of the two is Since they are different, a corrosion current flows between a metal having a large ionization tendency (base metal) and a small metal (precious metal). As a result, the base metal becomes metal ions and dissolves in the solution and is corroded. This is called foreign metal corrosion.

  For example, when a connection part of different metals gets wet due to running, car washing, or condensation in rainy weather, ionization of an aluminum base that is electrically base proceeds to promote corrosion. As a result, the contact state of the terminal part deteriorates and the electrical characteristics become unstable, the electrical resistance increases due to the increase in contact resistance and the wire diameter decreases due to corrosion, and further the disconnection causes malfunction of the electrical components, It is also possible to stop functioning.

  In particular, when aluminum-based terminals and copper-based terminals are connected among different types of metal terminals, the difference in standard electrode potential between the terminals increases, so that electric corrosion tends to occur.

As a conventional method for preventing the occurrence of such electric corrosion, Patent Document 1 below proposes an aluminum wire terminal.
In the terminal for an aluminum electric wire in Patent Document 1, the terminal rear end portion is formed of an aluminum-based material, the terminal tip end portion is formed of a copper-based material, the terminal rear end portion and the terminal tip end portion are joined, It is the connection terminal comprised by sealing a part with an insulator.

  According to Patent Document 1, it is possible to connect an aluminum electric wire to a terminal rear end portion formed of an aluminum-based material, and to connect a copper terminal of a counterpart to a terminal tip portion formed of a copper-based material. It is said that electrolytic corrosion can be prevented without the electrolytic solution adhering to the connecting portion by resin sealing the connecting portion between the front end portion and the terminal rear end portion.

  However, when resin sealing is performed as in Patent Document 1, the structure and the manufacturing process are complicated, and the amount of resin used is large, so that there is a problem that costs are increased.

  On the other hand, it is conceivable to use a waterproof connector, but if cracks occur due to vibration fatigue or aging deterioration, once rainwater or the like enters the waterproof connector from this crack, it reverses the result of galvanic corrosion. .

  Therefore, it is conceivable to seal only the necessary portions with resin. However, when the resin that coats the connection part between the terminal front end and the terminal rear end is a resin having a low viscosity before curing, it is rich in diffusibility and fluidity, so when a low viscosity resin is supplied to the connection part In addition, the layer thickness is reduced, and the electrolyte solution is likely to penetrate. As a result, there has been a problem that electrolytic corrosion of the connection portion between the terminal front end portion and the terminal rear end portion occurs due to the permeated electrolytic solution.

  In addition, when the viscosity before curing is a low viscosity resin of 500 mPa · S or less, a part of the resin supplied to the connection part flows to the mating terminal connection part, causing a poor connection with the mating terminal. There was a difficulty of becoming.

  Furthermore, in the case of a low-viscosity resin, it takes time and effort to repeatedly coat and cure the resin many times in order to ensure the coating thickness. There was also a problem that it penetrated and the connection part was eroded.

  On the other hand, when the resin that seals the connection portion is a high-viscosity resin, the minute gap existing in the connection portion cannot be reliably filled. It had the difficulty of reaching food.

  Further, in the case of a resin having a high viscosity before curing, since it is difficult to spread when applied, the contact area of the resin with the connection portion is reduced, the integrity is impaired, and the connection portion is easily peeled off. When peeled off, the electrolyte infiltrates and adheres to the connection portion, which has the disadvantage of leading to electrolytic corrosion.

JP 2004-111058 A

  Therefore, the present invention prevents the occurrence of dissimilar metal contact corrosion that the conductor corrodes by contact between the conductor and a connection terminal made of a metal that is noble than the metal constituting the conductor, and has stable electrical characteristics over time. It is an object of the present invention to provide a connection structure having a structure and a method for manufacturing the connection structure.

  The present invention comprises a coated electric wire provided with a wire tip that coats a conductor with an insulating coating, peels off the insulating coating on the tip side and exposes the conductor, and a wire connecting portion that connects the wire tip. A connection structure composed of a connection terminal composed of a metal nobler than the metal composing the conductor and an insulating resin sealing the tip end of the electric wire connected to the electric wire connecting portion, the insulating resin It is characterized by comprising two or more kinds of resins having different viscosities before curing.

  As an aspect of the present invention, the insulating resin is composed of a first insulating resin and a second insulating resin having a higher oligomer ratio and a lower monomer ratio than the first insulating resin, and the first insulating resin Each of the second insulating resins can be composed of the same main component.

  Further, as an aspect of the present invention, the first insulating resin is a resin having a viscosity capable of penetrating into a gap of 50 μm or less before curing, and the second insulating resin has a viscosity before curing that is higher than that of the first insulating resin. A resin-sealed portion in which the wire tip is sealed with the insulating resin, a first resin-sealed portion that covers the surface of the wire tip with the first insulating resin, It can comprise with the 2nd resin sealing part which coat | covers the outer surface of 1 resin sealing part with said 2nd insulating resin.

  As an aspect of the present invention, the first insulating resin is a low-viscosity resin having a viscosity before curing of 2,000 mPa · s or less, and the second insulating resin is 5,000 mPa · s or more in viscosity before curing. The high viscosity resin can be obtained.

  As an aspect of the present invention, the first insulating resin may have a viscosity before curing of 500 mPa · s or more, and the second insulating resin may have a viscosity of 20,000 mPa · s or less.

  As an aspect of the present invention, the insulating resin covering the surface of the exposed conductor exposed from the wire connecting portion at the wire tip can be formed with a thickness of at least 200 μm.

  As an aspect of the present invention, the insulating resin is a resin having a Shore D hardness of 40 to 80 and an adhesive strength to a metal of 3 MPa or more and an elastic modulus of 200 MPa or more and 1000 MPa or less in a range of −40 ° C. to 125 ° C. be able to.

  Moreover, as an aspect of the present invention, the connection structure includes the insulating resin made of silicon, acrylic, urethane, polyamide, epoxy, fluorine, polyvinyl butyral, phenol, polyimide, or acrylic rubber. At least one of the resins can be used.

  As an aspect of the present invention, the conductor can be made of an aluminum-based material, and the connection terminal can be made of a copper-based material.

  Further, according to the present invention, in the covered electric wire covering the conductor with an insulating coating, the electric wire tip portion where the insulating coating on the tip end side is peeled and the conductor is exposed is made of a metal nobler than the metal constituting the covered electric wire. A method of manufacturing a connection structure that is connected to an electric wire connection provided in a connection terminal and seals the electric wire tip connected to the electric wire connection with an insulating resin, wherein the electric wire tip is sealed with the insulating resin. Two or more types including a first insulating resin having a viscosity capable of penetrating into a gap having a viscosity before curing of at least 50 μm and a second insulating resin having a viscosity before curing higher than that of the first insulating resin. A first resin coating step of coating the surface of the wire tip with the first insulating resin, and after the first resin coating step, the outer surface of the first insulating resin is applied to the second insulating resin. 2nd resin seal coater to coat with And performing.

  As an aspect of the present invention, an ultraviolet irradiation step in which the insulating resin is made of an ultraviolet curable resin and the insulating resin is cured by irradiating with ultraviolet rays is performed between the first resin coating step and the second resin coating step. Instead, it can be performed after the second resin coating step.

  The connection between the wire connection portion and the wire tip is not limited to the connection by crimping, for example, welding such as ultrasonic welding, or using an adhesive or tape having conductivity by containing metal particles or the like. It may be a connection.

  The connection terminals include both female terminals and male terminals.

  The insulating resin is not limited to being composed of two types of insulating resins, but may be composed of three or more types of insulating resins depending on the viscosity.

  The insulating resin may contain a filler. Examples of the filler include silica such as crystalline silica and synthetic silica, and inorganic filler such as alumina and glass balloon.

  In addition, the range described using the symbol “to” in the claims and the specification of the present invention includes the numerical value described before the symbol and the numerical value described after the symbol.

  According to the present invention, it is possible to prevent the occurrence of dissimilar metal contact corrosion in which a conductor corrodes due to contact between a conductor and a connection terminal made of a metal nobler than the metal constituting the conductor. A connection structure having characteristics and a method for manufacturing the connection structure can be provided.

The perspective view of the crimp terminal part of the electric wire with a crimp terminal of this embodiment. Explanatory drawing of the crimp terminal of this embodiment. Structure explanatory drawing of the crimp terminal part of the electric wire with a crimp terminal of this embodiment. Explanatory drawing which showed the crimp terminal part of the electric wire with a crimp terminal seen from the side in a partial cross section. FIG. 5 is a cross-sectional view taken along line AA in FIG. 4. Explanatory drawing which represented a mode that the resin sealing part of this embodiment was formed in a cross section. Explanatory drawing which represented a mode that the resin sealing part of this embodiment was formed in a cross section.

An embodiment of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1 to 5, the electric wire 1 with a crimp terminal of the present embodiment includes a crimp terminal 10, a covered electric wire 40, and a resin sealing portion 29.

  FIG. 1 is an external view of a crimp terminal portion of a wire 1 with a crimp terminal according to the present embodiment. FIG. 2A is a diagram with a crimp terminal according to the present embodiment in which a resin sealing portion 29 described later is indicated by a virtual line. 1 is a perspective view of a portion including a crimp terminal 10 of an electric wire 1. FIG. 2B is an external view of the crimp terminal 10 and the covered electric wire 40 before crimping. FIG. 3 shows a portion including the crimp terminal 10 of the electric wire 1 with the crimp terminal of the present embodiment in which the crimp terminal 10 is represented by cutting the intermediate portion in the width direction Y from the front end portion in the longitudinal direction X to the front portion of the rear end portion. It is explanatory drawing which shows. FIG. 4 is an explanatory view showing a part of the crimp terminal of the electric wire with crimp terminal as viewed from the side, and FIG. 5 is a sectional view taken along line AA in FIG.

  As shown in FIG. 2 (b), the coated electric wire 40 has a core wire 43 formed by twisting a thin aluminum electric wire as compared with a conventional stranded wire in accordance with recent miniaturization and weight reduction. It coat | covers with the insulation coating 41 comprised with resin. On the distal end side of the covered electric wire 40, an electric wire tip portion 42 is formed by peeling off the insulating coating 41 and exposing the covered electric wire 40.

  The crimp terminal 10 is a female terminal, and as shown in FIG. 2 (a), from the front to the rear in the longitudinal direction X, the box part 11 that allows insertion of a male terminal of a male terminal (not shown); A wire barrel portion 12 is disposed behind the box portion 11 via a first transition 18 having a predetermined length, and is disposed behind a wire barrel portion 12 via a second transition 19 having a predetermined length. The insulation barrel portion 15 is integrally formed.

  As shown in FIG. 2 (b), the wire barrel portion 12 before crimping is composed of a barrel bottom portion 13 and wire barrel pieces 14 extending obliquely outward and upward from both sides in the width direction Y. It is formed in a U shape. The insulation barrel portion 15 before crimping is also composed of a barrel bottom portion 16 and an insulation barrel piece 17 extending obliquely outward and upward from both sides in the width direction Y, and is formed in a substantially U shape in rear view.

  As shown in FIG. 2A, an electric wire connecting portion 21 to which an electric wire front end portion 42 of the covered electric wire 40 is connected is configured at the rear portion in the longitudinal direction X of the crimp terminal 10.

  The wire connection portion 21 is, in order from the rear in the longitudinal direction X to the distal end side, a core wire crimping portion constituted by a covered wire crimping portion 21a constituted by the insulation barrel portion 15 or the like, a rear side core wire exposed portion 21b, an insulation barrel piece 17 or the like. It consists of the part 21c and the front end side core wire exposed part 21d.

  More specifically, the covered wire crimping portion 21 a is a portion where the insulation coating 41 of the covered wire 40 is crimped by the insulation barrel portion 15. The rear-side core wire exposed portion 21b is an exposed core wire portion where the core wire 43 is exposed without being covered by the insulation coating 41 or the barrel pieces 14 and 17 in the second transition 19 between the covered wire crimp portion 21a and the core wire crimp portion 21c. It is. The core wire crimping portion 21 c is a portion where the core wire 43 of the covered electric wire 40 is crimped by the wire barrel portion 12 and crimped. The distal end side core wire exposed portion 21d is an exposed core portion where the core wire 43 is exposed without being covered with the insulating coating 41 or the wire barrel piece 14 in the first transition 18 on the front side of the core wire crimping portion 21c.

  The crimp terminal 10 has a three-dimensional structure by using a copper alloy strip (FAS680H material, manufactured by Furukawa Electric Co., Ltd.) having a thickness of 0.25 mm and a width of 31 mm as a metal substrate and bending the metal substrate.

  The box portion 11 is formed of an inverted hollow rectangular column, and the internal space of the box portion 11 communicates with the longitudinal direction X before the resin sealing portion 29 is formed on the crimp terminal 10. Here, the opening A that opens at the rear end in the longitudinal direction X of the box portion 11 is set as the rear end opening Ar.

  The box part 11 is functionally divided into three parts in order from the front to the rear in the longitudinal direction X as shown in FIG. Specifically, a female connection portion 23 that connects to each inserted male terminal (not shown), and a housing mounting portion that is attached in a state where the box portion 11 is housed in a terminal housing recess (not shown) formed in the connector housing. 24 and an internal space 26 </ b> A that allows inflow of the insulating resin 50 that forms the resin sealing portion 29, and is a resin inflow allowing portion 26 that is configured in the rear portion of the box portion 11.

  The female connection portion 23 of the box portion 11 includes a space 23 </ b> A that allows insertion of a male terminal male tab therein, and a contact piece 23 a that contacts the male terminal male tab to be inserted.

  The housing mounting portion 24 of the box portion 11 includes a housing mounting protruding piece 25 formed so as to protrude downward so as to be inserted into a groove portion (not shown) formed on the connector housing side, and a convex portion (illustrated) formed on the connector housing side. (Omitted) is provided with a housing mounting opening Ad that allows insertion into the internal space 24A. The housing mounting protrusions 25 are formed projecting downward at both ends in the width direction Y of the bottom portion of the box portion 11, and the housing mounting openings Ad are formed by opening the bottom portion of the box portion 11.

  The resin inflow permitting portion 26 of the box portion 11 includes an internal space 26 </ b> A that allows the resin sealing portion 29 to be formed therein.

In the crimp terminal 10 configured in this manner, a resin sealing portion 29 that covers the entire surface of the wire connection portion 21 in a state where the wire tip portion 42 is crimped is formed.
The resin sealing portion 29 is formed on the entire surface of the electric wire connecting portion 21, and in particular, the rear side core wire exposed portion 21 b which is a core wire exposed portion exposed without being covered with the insulating coating 41 or the barrel pieces 14, 17, and The tip-side core wire exposed part 21d is formed to have a thickness of at least 200 μm.

  The resin sealing portion 29 includes a first resin sealing portion 29A that covers the surface of the wire tip portion 42 and a second resin sealing portion 29B that mainly covers the outer surface of the first resin sealing portion 29A. .

  Subsequently, the insulating resin 50 constituting the resin sealing portion 29 will be described.

  The insulating resin 50 is composed of a first insulating resin 50A that constitutes the first resin sealing portion 29A and a second insulating resin 50B that constitutes the second resin sealing portion 29B. It is comprised with the resin material from which the viscosity at the time of applying to 21 differs.

  The first insulating resin 50A is a low-viscosity resin that can penetrate into a gap having a viscosity before curing of 50 μm or less, and the second insulating resin 50B has a higher oligomer ratio than the first insulating resin 50A. The first insulating resin 50A and the second insulating resin 50B are preferably composed of the same main component, respectively, with a low ratio and high viscosity resin.

  Specifically, the first insulating resin 50A is a resin having a viscosity before curing of 500 to 2,000 mPa · s measured using a BH type rotational viscometer under conditions of 25 ° C. based on the provisions of “JIS K6251”. Made of material.

  The second insulating resin 50B is made of a resin material having a viscosity before curing of 5,000 to 20,000 mPa · s measured under the same conditions as the first insulating resin 50A based on the provisions of “JIS K6251”.

  Furthermore, both the first insulating resin 50A and the second insulating resin 50B are made of a resin material having a measured Shore D hardness of 40 to 80 under a condition of 25 ° C. based on the provisions of “JIS K6253”.

  Furthermore, both the first insulating resin 50A and the second insulating resin 50B are made of a resin material having an adhesive strength to metal measured based on the provisions of “JIS K6849” of 3 MPa or more in the range of −40 ° C. to 125 ° C. .

  The first insulating resin 50A and the second insulating resin 50B are both made of a resin material having an elastic modulus of 200 MPa or more and 1000 MPa or less measured based on the provisions of “JIS K6251”.

  Furthermore, both the first insulating resin 50A and the second insulating resin 50B have a boiling water absorption rate of 1.0% or less, expressed as a weight change rate when boiled for 2 hours, and are resistant to hydrolysis with respect to the electrolytic solution (water). It consists of a resin material with excellent decomposability.

  Examples of the first insulating resin 50A and the second insulating resin 50B described above include, for example, silicon-based, acrylic-based, urethane-based, polyamide-based, epoxy-based, fluorine-based, polyvinyl butyral-based, phenol-based, polyimide-based, and acrylic rubber-based. Any one of the resin materials can be configured as the same main component.

Next, a method for forming the resin sealing portion 29 on the surface of the wire connecting portion 21 will be described with reference to FIGS.
6A, 6 </ b> B, and 7 are explanatory views illustrating a state in which the resin sealing portion 29 is formed on the surface of the wire connection portion 21 in a partially enlarged view.

  First, the 1st resin coating process which coat | covers the surface of the electric wire connection part 21 with 1st insulating resin 50A is performed. In the first resin coating step, as shown in FIG. 6A, the first insulating resin 50 </ b> A is dropped onto the electric wire connection portion 21. Since the first insulating resin 50A has a low viscosity, for example, the first insulating resin 50A penetrates into a slight gap between the plurality of core wires 43 constituting the rear side core wire exposed portion 21b and the front end side core wire exposed portion 21d and A film-like first resin sealing portion 29 </ b> A that extends over the entire surface (see a partially enlarged view in FIG. 6A) and covers the surface of the wire connection portion 21 can be formed.

  Since the first insulating resin 50 </ b> A has a low viscosity, the thickness of the first resin sealing portion 29 </ b> A that covers the wire connection portion 21 is thin, but the first resin sealing portion 29 </ b> A is formed on the surface of each core wire 43. Is coated with the first insulating resin 50A.

  Then, the 2nd resin sealing coating process which coat | covers the outer surface of 1st insulating resin 50A with 2nd insulating resin 50B is performed. In the second resin sealing and covering step, as shown in FIG. 6B, the second insulating resin 50B is dropped on the surface of the first insulating resin 50A that covers the surface of the wire connecting portion 21. Since the first insulating resin 50A has a high viscosity, it does not spread over a wide range, and the second resin sealing portion 29B that covers the wire connecting portion 21 in a bulky manner can be formed (one in FIG. 6B). (See enlarged view).

  After continuously performing the first resin coating step and the second resin sealing coating step in this way, as shown in FIG. 7, the first insulating resin 50A and the second insulating resin coated on the surface of the wire connecting portion 21 are used. The first insulating resin 50A and the second insulating resin 50B can be cured by irradiating 50B with ultraviolet light, and from two layers of the first resin sealing portion 29A and the second resin sealing portion 29B. The resin sealing portion 29 to be formed can be formed without an interface (see a partially enlarged view in FIG. 7).

  When the photopolymerization initiator is a cationic polymerization initiator, cations are generated as active species, and cationic polymerization occurs. When the photopolymerization initiator is a radical polymerization initiator, radicals are generated as active species and radical polymerization occurs.

Through the steps described above, the electric wire 1 with a crimp terminal as shown in FIGS. 1 to 5 can be configured, and the electric wire 1 with a crimp terminal having such a configuration can obtain various actions and effects as follows.
The electric wire 1 with a crimp terminal includes a covered electric wire 40 including an electric wire tip 42 in which a core wire 43 is covered with an insulating coating 41 and the insulating coating 41 on the tip side is peeled to expose the core wire 43, and the electric wire tip portion Insulating resin that seals the wire terminal portion 42 that is connected to the wire barrel portion 12 and the crimp terminal 10 that includes the wire barrel portion 12 that connects the wire 42 and is made of a metal that is nobler than the metal that forms the core wire 43. 50, and the insulating resin 50 is composed of two types of insulating resins 50A and 50B having different viscosities before curing.

  With the above-described configuration, the core wire 43 which is a different metal and the crimp terminal 10 come into contact with each other, and the electrolytic solution adheres, so that electrolytic corrosion occurs between the crimp terminal 10 and the core wire 43 which is a base metal than the crimp terminal 10. It is possible to provide the electric wire 1 with a crimp terminal that effectively prevents the occurrence and has stable electrical characteristics over time.

  Specifically, when the electrolytic solution adheres in a state where different types of metals such as aluminum constituting the core wire 43 and copper alloy constituting the crimp terminal 10 are in contact with each other, the standard electrode potentials of the two are different, and thus ionization tendency Corrosion current flows between a large metal (base metal: aluminum constituting the core wire 43 in this embodiment) and a small metal (noble metal: copper alloy constituting the metal substrate in this embodiment). As a result, the base metal becomes metal ions and dissolves in the solution and is corroded.

  On the other hand, the electric wire 1 with a crimp terminal has a configuration in which the electric wire tip portion 42 is sealed with two or more kinds of the insulating resins 50 having different viscosities. For this reason, the first insulating resin 50 </ b> A having a low viscosity can penetrate into the minute gaps of the wire tip 42 and coat the surface of each core wire 43. And the whole surface of the electric wire front-end | tip part 42 can be coat | covered with 50 A of 1st insulating resin with a low viscosity by spreading over the whole electric-wire front-end | tip part 42.

  Furthermore, since the first insulating resin 50A has a low viscosity, the film thickness of the first resin sealing portion 29A that covers the wire connecting portion 21 is thin. The portion 42 can be coated with a sufficient film thickness from the viewpoint of corrosion resistance.

  Thus, the electric wire front-end | tip part 42 can be sealed firmly with the 1st insulating resin 50A and the 2nd insulating resin 50B from which a viscosity differs, and the electric wire 1 with a crimp terminal can acquire the outstanding anticorrosion effect.

  The insulating resin 50 includes a first insulating resin 50A and a second insulating resin 50B having a higher oligomer ratio and a lower monomer ratio than the first insulating resin 50A, and the first insulating resin 50A. And the second insulating resin 50B are composed of the same main component. However, the adjustment of the viscosity is not limited to this. For example, the viscosity may be adjusted by changing the content of the filler.

  With the above configuration, the second insulating resin 50B has a higher viscosity than the first insulating resin 50A, and the electric wire tip 42 can be sealed with resins having different viscosities.

  Further, by configuring the first insulating resin 50A and the second insulating resin 50B having different viscosities with the same main component, when the respective insulating resins 50 are laminated and coated on the wire connection portion 21, the first insulating resin 50A and the second insulating resin 50B are easily adapted to each other. There is no interface between the resin 50A and the second insulating resin 50B.

  Therefore, the second insulating resin 50B does not peel from the first insulating resin 50A, and it is possible to prevent the electrolytic solution from entering between the first insulating resin 50A and the second insulating resin 50B. Anticorrosive effect can be obtained.

  In the electric wire 1 with a crimp terminal, the first insulating resin 50A is a resin having a viscosity capable of penetrating into a gap of 50 μm or less, the second insulating resin 50B is a resin having a higher viscosity than the first insulating resin 50A, A resin sealing portion 29 in which the wire tip 42 is sealed with the insulating resin 50; a first resin sealing portion 29A that covers the surface of the wire tip 42 with the first insulating resin 50A; The outer surface of one resin sealing portion 29A is composed of a second resin sealing portion 29B that covers the second insulating resin 50B.

  As described above, the first insulating resin 50A and the second resin sealing portion 29B are covered with the above-described laminated structure, whereby the first insulating resin 50A that is a low-viscosity resin and the second resin seal that is a high-viscosity resin. The resin sealing portion 29 can be formed by taking advantage of the difference in the viscosity of both the resin and the stopper portion 29B, and an excellent anticorrosion effect can be obtained.

  Specifically, the core wire 43 of the wire connection portion 21 is coated with the first insulation resin 50A by allowing the first insulation resin 50A to penetrate into a minute gap of 50 μm or less on the surface of the wire connection portion 21, The entire wire tip 42 can be spread.

  Furthermore, the first insulating resin 50 </ b> A can be coated over a wide range, that is, the entire surface of the wire connecting portion 21.

Therefore, the electric wire connecting portion 21 can be coated with the first insulating resin 50A, and a wide contact area with the electric wire tip 42 can be secured, and the details between the core wire 43 and the crimp terminal 10 are the first. Since the insulating resin 50A is spread and spread, the contact area between the wire connecting portion 21 including the wire tip 42 and the first insulating resin 50A can be increased.
Further, the first insulating resin 50 </ b> A can be firmly covered with the wire connecting portion 21 without being peeled off.

  On the other hand, by covering the outer surface of the first resin sealing portion 29A with the second insulating resin 50B having a viscosity higher than that of the first insulating resin 50A, a sufficient film thickness is secured to ensure corrosion resistance. be able to.

  In the electric wire 1 with a crimp terminal, the first insulating resin 50A is a low-viscosity resin having a viscosity of 2,000 mPa · s or less, and the second insulating resin 50B is a high-viscosity having a viscosity of 5,000 mPa · s or more. It can be a resin.

  In this way, by setting the viscosity of the first insulating resin 50A to 2,000 mPa · s or less, it is possible to cover the entire wire connection portion 21 by diffusing with a sufficient contact area while penetrating into a minute gap. it can.

  On the other hand, by setting the viscosity of the second insulating resin 50B to 5,000 mPa · s or more, it is possible to cover the first resin sealing portion 29A while securing a sufficient film thickness.

  More preferably, in the electric wire 1 with a crimp terminal, the first insulating resin 50A is a low-viscosity resin having a viscosity in the range of 500 to 2,000 mPa · s, and the second insulating resin 50B has a viscosity of 5 , 20,000 to 20,000 mPa · s.

  In this way, by setting the viscosity of the first insulating resin 50A to 500 mPa · s or more, when the wire connecting portion 21 is covered with the first insulating resin 50A, the tip end side of the crimp terminal 10, that is, the box portion 11 The first insulating resin 50 </ b> A does not flow into the inside, and when the male tab of the male terminal serving as the connection partner is inserted into the box portion 11, it is possible to prevent a situation that causes connection failure.

  Furthermore, since the first insulating resin 50A dropped on the wire connection portion 21 does not diffuse excessively and the thickness thereof does not become extremely thin, the first insulating resin 50A is secured with a minimum necessary film thickness. Thus, the surface of the wire connecting portion 21 can be covered.

  In addition, by setting the viscosity of the second insulating resin 50B to 20,000 mPa · s or less in this way, the viscosity is too high, resulting in poor diffusibility, and the surface of the first insulating resin 50A is covered with the second insulating resin 50B. The situation where it takes time to coat can be prevented. Furthermore, since the coating that the surface of the first insulating resin 50 </ b> A cannot be completely coated does not occur, the necessary anticorrosive property can be reliably obtained.

  In the electric wire 1 with a crimp terminal, the thickness of the resin-sealed portion 29 formed on the rear side core wire exposed portion 21b as the exposed conductor exposed from the wire barrel portion 12 in the electric wire connecting portion 21 and the front end side core wire exposed portion 21d. The surface of the rear-side core wire exposed portion 21b and the front-side core wire exposed portion 21d that are liable to adhere and erode due to being exposed from the wire barrel portion 12 is 200 μm or more. It is possible to secure a sufficient film thickness so that it can be tightly sealed and to reliably prevent electrolytic corrosion.

  The first insulating resin 50A and the second insulating resin 50B have a Shore D hardness of 40 to 80, an adhesive strength to metal of 3 MPa or more and a modulus of elasticity of 200 MPa or more and 1000 MPa or less in a range of −40 ° C. to 125 ° C. By using resin, the resin sealing part 29 formed in the electric wire connection part 21 can be made difficult to peel from the electric wire connection part 21.

  Therefore, the electrolyte solution can be prevented from entering, and the battery can be configured with excellent durability without causing electrolytic corrosion.

  Moreover, since the electric wire 1 with a crimp terminal of this embodiment forms the core wire 43 with an aluminum-type material, and forms the said crimp terminal 10 with a copper-type material, it can obtain the outstanding electroconductive performance. , Fuel consumption can be improved.

  Specifically, by forming the core wire 43 from an aluminum-based material in this way, the cost can be reduced, the vehicle can be reduced in weight, and fuel efficiency can be improved.

  Furthermore, when connecting aluminum-based materials and copper-based materials among different types of metal terminals, the standard electrode potential difference between them is particularly large, so that electric corrosion tends to occur. Like the electric wire 1, the insulating resin 50 is made of two or more types of resins having different viscosities, so that the resin sealing portion 29 utilizing the difference in viscosity can be formed in the electric wire connecting portion 21. It is possible to prevent electrolytic corrosion.

  Moreover, in the manufacturing method of the electric wire 1 with a crimp terminal according to the present embodiment, the first insulating resin 50A having a viscosity capable of permeating the electric wire tip end portion 42 with the insulating resin 50 into a gap of at least 50 μm and the first insulation. Using the second insulating resin 50B having a viscosity higher than that of the resin 50A, a first resin coating step of covering the surface of the wire connection portion 21 with the first insulating resin 50A is performed, and after the first resin coating step, the first insulation is performed. This is a manufacturing method for performing a second resin sealing coating step of coating the surface of the resin 50A with the second insulating resin 50B.

  In the first resin coating step, the wire connecting portion 21 is covered with the first insulating resin 50A having a low viscosity that penetrates into the minute gap of 50 μm or less. The first insulating resin 50 </ b> A can be permeated up to and the entire surface of the wire connection portion 21 can be covered.

  Furthermore, in the second resin coating step, the outer surface of the first resin sealing portion 29A covered on the entire surface of the electric wire connecting portion 21 using the second insulating resin 50B having a higher viscosity than the first insulating resin 50A. Since this is a coating step, the coating of the wire connection portion 21 that is insufficient with the film thickness of the first insulating resin 50A can be supplemented with the second insulating resin 50B.

  In this way, an excellent anticorrosion effect that makes use of the characteristics due to the difference in viscosity between the first resin sealing portion 29A and the second resin sealing portion 29B can be obtained.

  In the method of manufacturing the electric wire 1 with the crimp terminal, the insulating resin 50 is made of an ultraviolet curable resin, and an ultraviolet irradiation process in which the insulating resin 50 is cured by irradiating with an ultraviolet ray includes the first resin coating process and the second resin. It is a manufacturing method performed after a said 2nd resin coating process, without performing between coating processes.

  By such a manufacturing method, the first resin sealing portion 29A and the second resin sealing portion 29B are integrated with each other without causing an interface between the first resin sealing portion 29A and the second resin sealing portion 29B. It is possible to form the resin-sealed portion 29 having excellent properties, prevent the electrolyte from entering due to peeling, and obtain an excellent anticorrosive effect.

Then, the effect confirmation test performed in order to confirm the effect of the electric wire 1 with a crimp terminal of this embodiment is demonstrated.
In this effect confirmation test, a resin sealing portion 29 is formed on the wire connection portion 21 according to the viscosity of the insulating resin 50 for each of the plurality of wires with crimp terminals as a sample, and the anticorrosion for each of the resin sealing portions 29 is formed. By comparing the performance, the effect of the combination according to the viscosity of the two types of insulating resins 50 constituting the resin sealing portion 29 of the present embodiment was confirmed.

  The resin sealing portion 29 includes a resin sealing portion 29 formed only from the low-viscosity first insulating resin 50A, a resin sealing portion 29 formed only from the high-viscosity second insulating resin 50B, and the first insulating resin 50A. The resin sealing portion 29 formed of two types of insulating resins 50 with the second insulating resin 50B was formed.

  Of these, the resin sealing portion 29 formed of two types of insulating resins 50 is configured by the above-described laminated structure of the first resin sealing portion 29A and the second resin sealing portion 29B.

Furthermore, using the first insulating resin 50A and the second insulating resin 50B having different viscosities as described above, the monomer and oligomer constituting the first insulating resin 50A, and the monomer and oligomer constituting the second insulating resin 50B are: Of the resin materials described above, the same kind of resin material was used as the main component.
Specifically, the first insulating resin 50A and the second insulating resin 50B are silicon, acrylic, urethane, polyamide, epoxy, fluorine, polyvinyl butyral, phenol, polyimide, and acrylic rubber. Of these, the same kind of resin material was used as the main component.

  The first insulating resin 50A has viscosities (mPa · s) of 230, 500, 730, 1,200, 1,750, 1,800, 2,000, and 2,100, all from the second insulating resin 50B. Also, seven types of resins having different viscosities with low viscosity were used.

  As the second insulating resin 50B, the viscosity (mPa · s) is 3,500, 5,000, 5,500, 6,300, 6500, 7,000, 8,000, 8,500, 10,000, 11 15 kinds of resins having different viscosities higher than the first insulating resin 50A were used, namely, 15,000, 15,000, 16,500, 17,000, 20,000, and 24,000.

  In this effect confirmation experiment, samples are prepared with various combinations of the first insulating resin 50A and the second insulating resin 50B described above for each of the cross-sectional areas of the core wire 43 of the crimp-attached electric wire having 0.75 sq and 2.5 sq. And the resistance fluctuation value of the electric wire connection part 21 which formed the resin sealing part 29 for every sample was computed, and anticorrosion performance was compared based on these.

As for the resistance fluctuation value, the initial resistance value for each electric wire connection portion 21 is measured, and the resistance value for each electric wire connection portion 21 is measured after exposing each electric wire to an environment to be described later. Calculated.
The resistance was measured using a resistance measuring instrument (ACmΩHiTESTER 3560, manufactured by Hioki Electric Co., Ltd.).

  In this effect confirmation test, in order to confirm erosion resistance that can withstand actual use, after measuring the initial resistance value, after exposing a plurality of electric wires to high temperature exposure (120 ° C. × 120 hours), JIS Z2371 The salt spray test (5% by weight saline solution at 35 ° C. is sprayed at a predetermined pressure) for 96 hours was carried out. Thereafter, the film was exposed to conditions of constant temperature and humidity (85 ° C., 95% RH × 96 h).

  Thereafter, as described above, the resistance value of the wire connection part 21 before and after the exposure is measured by measuring the resistance value in the same manner as the initial resistance measurement and subtracting the initial resistance value of the same sample. Values were calculated and the anticorrosion performance was compared based on these values.

  Here, it has been clarified that satisfying a resistance fluctuation value of 2.5 mΩ or less is effective for corrosion prevention.

  Based on the resistance fluctuation value of each sample and the sealing state of the resin of the electric wire connection portion 21, the samples were classified as shown in Table 1.

表１に示すとおり、分類Ａは、第１絶縁樹脂５０Ａの中でも、最も高粘度である粘度が２，１００（ｍＰａ・ｓ）の樹脂と、最も低粘度である粘度が２３０（ｍＰａ・ｓ）の樹脂とを除いて分類した第１絶縁樹脂５０Ａのみで分類されるグループである。

As shown in Table 1, the classification A is a resin having the highest viscosity of 2,100 (mPa · s) and the lowest viscosity of 230 (mPa · s) among the first insulating resins 50A. It is a group classified only by the first insulating resin 50A that is classified by excluding the above-mentioned resin.

  The classification B is a group classified only by the second insulating resin 50B having the viscosity of 20,000 and 24,000 (mPa · s), which is the top two types of high viscosity among the second insulating resins 50B.

  Further, as shown in Table 1, among the classifications C to K, for example, for the classifications E, H, I, J, and K, at least one of the first insulating resin 50A and the second insulating resin 50B is used. A plurality of resins having different viscosities are classified.

  For such classifications E, H, I, J, and K, a sample in which the resin sealing portion 29 is formed so as to be all combinations between the first insulating resin 50A and the second insulating resin 50B is created. The anticorrosion performance is compared.

  When comparing the average resistance fluctuation values for each of classifications A to K, among the classifications A to K, the average resistance fluctuation values for classifications A to I and K were both greater than 2.5 mΩ, and the corrosion performance was not good. On the other hand, the average resistance fluctuation value in the classification of J was 2.5 mΩ or less, which resulted in excellent corrosion performance.

  From the above, it was possible to confirm the excellent anticorrosion performance of the electric wire 1 with crimp terminal of the present embodiment.

  Further, according to this effect confirmation test, of the two types of resins used, the first insulating resin 50A has a viscosity of 500 to 2,000 (mPa · s), and the second insulating resin 50B has a viscosity of 5,000 to 5,000. It was revealed that 20,000 (mPa · s) is optimal.

  More specifically, in the case of the first resin sealing portion 29A formed using the first insulating resin 50A having a viscosity of less than 500 mPa · s as in the categories C, D, and E, the resistance fluctuation value is 2. In addition to the value exceeding 5 mΩ, when the first resin sealing portion 29A was observed, a sample in which the first insulating resin 50A had flowed into the box portion 11 was also confirmed. In this case, when the male tab of the male terminal on the connection partner side is inserted into the box portion 11, it causes a connection failure and thus has a functional difficulty. Further, the wire connection portion 21 had a portion covered only with a very thin film.

  This also revealed that the viscosity of the first insulating resin 50A is preferably 500 mPa · s or more.

  In addition, in the case of the resin sealing portion 29 formed using the first insulating resin 50A having a viscosity greater than 2,000 mPa · s as in the categories F, G, and H, the resistance fluctuation value is 2.5 mΩ. The value exceeded. This is considered to be because when the viscosity exceeds 2,000 mPa · s, it is difficult to penetrate into a minute gap of 50 μm or less. Moreover, when the resin sealing part 29 was observed, there existed what cannot be spread | diffused with sufficient contact area with respect to the electric wire connection part 21, and the whole could be coat | covered.

  From this, it became clear that the viscosity of the first insulating resin 50A is preferably 2,000 mPa · s or more.

  On the other hand, in the case of the resin sealing portion 29 formed using the second insulating resin 50B in which the viscosity of the second insulating resin 50B is less than 5,000 mPa · s, as in the categories C, F, and I, the resistance fluctuation value In addition to the value exceeding 2.5 mΩ, the resin sealing portion 29 was observed, and when the second resin sealing portion 29B was covered, a sufficient layer thickness was secured to prevent electrolytic corrosion. There were many samples that could not.

  This revealed that the viscosity of the second insulating resin 50B is preferably 5,000 mPa · s or more.

  Moreover, in the case of the resin sealing portion 29 formed using the second insulating resin 50B having a viscosity exceeding 20,000 mPa · s, as in the classifications B, E, H, and K, the resistance fluctuation value exceeds 2.5 mΩ. In addition, since the permeability was poor, it could not be applied with a uniform film thickness, and it took time to form the resin sealing portion 29. Some samples had functional problems such as not being able to fit in the socket.

  From this, it has become clear that the viscosity of the second insulating resin 50B is preferably 20,000 mPa · s or less.

  Of the two types of resins used, the first insulating resin 50A has a viscosity of 500 to 2,000 (mPa · s) and the second insulating resin 50B has a viscosity of 5,000 to It became clear that the electric wire 1 with a crimp terminal of the present embodiment of 20,000 (mPa · s) is optimal from the viewpoint of both anticorrosion performance and function.

In the correspondence between the configuration of the present invention and the above-described embodiment,
The connection structure corresponds to the electric wire 1 with a crimp terminal, and similarly,
The connection terminal corresponds to the crimp terminal 10,
The conductor corresponds to the core wire 43,
The wire connection portion corresponds to the wire barrel portion 12,
The wire tip connected to the wire connecting portion corresponds to the wire connecting portion 21,
The exposed conductors correspond to the rear side core wire exposed portion 21b and the front end side core wire exposed portion 21d.

The present invention is not limited to the above-described embodiments, and can be configured in various embodiments.
For example, as another embodiment, the resin sealing portion 29 has a configuration in which a wire connection portion side opening Ar that opens on the wire connection portion 21 side in the longitudinal direction inside the box portion 11 is closed with the insulating resin 50. (Not shown).

  Thereby, it can prevent reliably that electrolyte solution flows in into the inside of the said box part 11 through the electric wire connection part side opening part Ar, and electrolyte solution retains in the inside of the said box part 11 over a long period of time. Therefore, the resin sealing portion 29 can be prevented from being hydrolyzed, and the occurrence of electrolytic corrosion can be reliably prevented.

  Moreover, you may form the damming part which dams the flow of the insulating resin 50 dripped at the electric wire connection part 21 as another embodiment in the crimp terminal 10 (not shown).

  Thereby, for example, when the insulating resin 50 dripped onto the electric wire connection portion 21 flows into the box portion 11 and the male tab of the male terminal on the connection partner side is inserted into the female connection portion 23, connection failure occurs. In addition, it is possible to prevent the insulating resin 50 from being excessively diffused and the film thickness from becoming too thin.

DESCRIPTION OF SYMBOLS 1 ... Electric wire with a crimp terminal 10 ... Crimp terminal 12 ... Wire barrel part 21 ... Electric wire connection part 21b ... Back side core wire exposed part 21d ... Tip side core wire exposed part 29A ... 1st resin sealing part 29B ... 2nd resin sealing part DESCRIPTION OF SYMBOLS 40 ... Covered electric wire 41 ... Insulation coating 42 ... Electric wire front-end | tip part 43 ... Core wire 50 ... Insulation resin 50A ... 1st insulation resin 50B ... 2nd insulation resin

Claims (11)

Covering the conductor with an insulation coating, stripping the insulation coating on the tip side and exposing the conductor, a covered electric wire with a wire tip,
A connection terminal comprising a wire connection part for connecting the wire tip part, made of a metal noble than the metal constituting the conductor,
A connection structure composed of an insulating resin that seals the wire tip connected to the wire connection portion,
The connection structure which comprised the said insulating resin with 2 or more types of resin from which the viscosity before hardening differs. The insulating resin,
A first insulating resin and a second insulating resin having a higher oligomer ratio and a lower monomer ratio than the first insulating resin;
The connection structure according to claim 1, wherein the first insulating resin and the second insulating resin are each composed of the same main component. The first insulating resin;
A resin having a viscosity that can penetrate into a gap of 50 μm or less before curing,
The second insulating resin;
The viscosity before curing is higher than that of the first insulating resin,
A resin sealing portion in which the wire tip is sealed with the insulating resin,
A first resin sealing portion that covers the surface of the tip portion of the electric wire with the first insulating resin;
The connection structure according to claim 1 or 2, comprising an outer surface of the first resin sealing portion and a second resin sealing portion that covers the second insulating resin. The first insulating resin is a low-viscosity resin having a viscosity before curing of 2,000 mPa · s or less,
The connection structure according to claim 3, wherein the second insulating resin is a high-viscosity resin having a viscosity before curing of 5,000 mPa · s or more. The first insulating resin has a viscosity before curing of 500 mPa · s or more,
The connection structure according to claim 4, wherein the second insulating resin has a viscosity before curing of 20,000 mPa · s or less. The connection structure according to any one of claims 1 to 5, wherein a thickness of the insulating resin covering a surface of an exposed conductor exposed from the electric wire connection portion at the electric wire tip is formed to be at least 200 µm. The insulating resin,
The connection structure according to claim 1 or 6, wherein a resin having a Shore D hardness of 40 to 80 and an adhesive strength to a metal of -40 ° C to 125 ° C of 3 MPa or more and an elastic modulus of 200 MPa to 1000 MPa is used. The insulating resin,
The resin according to any one of claims 1 to 7, wherein the resin is at least one of silicon, acrylic, urethane, polyamide, epoxy, fluorine, polyvinyl butyral, phenol, polyimide, and acrylic rubber. The connection structure described. The conductor is made of an aluminum-based material,
The connection structure according to claim 1, wherein the connection terminal is made of a copper-based material. In the covered electric wire covering the conductor with an insulating coating, the electric wire tip portion where the insulating coating on the tip side is peeled off to expose the conductor,
Connect to the wire connection part provided in the connection terminal composed of a noble metal than the metal constituting the covered wire,
A method of manufacturing a connection structure that seals the wire tip connected to the wire connection with an insulating resin,
A first insulating resin having a viscosity capable of penetrating into the gap having a viscosity before curing of at least 50 μm or less, and a second viscosity before curing higher than that of the first insulating resin. Using two or more types of resin including insulating resin,
Performing a first resin coating step of coating the surface of the wire tip with the first insulating resin;
The manufacturing method of the connection structure which performs the 2nd resin sealing coating process which coat | covers the outer surface of the said 1st insulating resin with the said 2nd insulating resin after the said 1st resin coating process. The insulating resin is composed of an ultraviolet curable resin,
11. The ultraviolet irradiation process for curing the insulating resin by irradiating with ultraviolet light is performed after the second resin coating process without being performed between the first resin coating process and the second resin coating process. Method for manufacturing the connection structure of the present invention.

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